activity vertically through the water column, and subsurface 
samples were collected for bacteriological and chemical 
analyses. All surface samples for bacteriological analyses 
(dye patch, underway, and profile stations) were collected 
in sterile one gallon jars and the identical samples were also 
used for measurements of radioactivity and chlorinity. 
A description of the equipment used, the method penis 
culating dilutions, and the data showing the position and 
intensity of the surface and subsurface radioactive fields at 
various times is given in the report of the Nuclear Science 
and Engineering Corporation, June 29, 1956.1 
Dilution of Radioactivity with Time 
Radioactivity was first detected in the boil at about 0747. 
Its intensity rapidly reached a plateau that was maintained until 
the VELERO IV left the boil for the first traverse pattern at 
0901. During this period, dilution of the effluent as calculated 
from the radioactivity, ranged from 1/12.5 to 1/100 with most 
of the values clustered around 1/25. The observed variations 
were probably due in part to the VELERO IV moving in and out of 
the boil during measurements, and in part to variations in the 
rate of feed of the tracer into and mixing with the effluent. 
The initial measurements on the subsurface radioactivity showed 
that essentially all of the tagged effluent rose to the surface 
of the ocean at the point of discharge. 
There was a consistent and fairly rapid dilution of the 
radioactivity as the tagged effluent field moved away from the 
the boil. The change with time is plotted in Figure 1 which 
1. Referred to in the text as the “NSE report”. 
